燃煤电厂脱硫废水COD及氨氮协同处理实验研究

Experimental Study on Synergistic Treatment of COD and Ammonia Nitrogen in Flue Gas Desulfurization Wastewater from Coal-fired Power Plants

实验研究旨在处理燃煤电厂湿法脱硫废水中的COD和氨氮,采用次氯酸钠、芬顿氧化法、MAP沉淀法和电催化氧化法处理实际脱硫废水,以达到《污水综合排放标准》(GB 8978-1996)一级排放标准氨氮为15 mg/l,COD为100 mg/l。实验结果显示,在次氯酸钠投加质量比为1:8时,可使得氨氮浓度达标;芬顿氧化法中双氧水投加量为3.5 mL/L、与硫酸亚铁摩尔比为1:3时,COD去除率可达57%;MAP沉淀法利用原有镁离子可达58%的氨氮去除率;但仅有电催化氧化法能处理氨氮、COD均达标。综合实际情况,采用前端喷氨优化-次氯酸钠氧化-电催化的处理组合工艺路线是经济高效的达标排放方法。

This study addresses the issues of COD and ammonia nitrogen in the wet desulfurization wastewater of a coal-fired power plant.Actual desulfurization wastewater was treated using sodium hypochlorite,Fenton oxidation,MAP precipitation,and electrocatalytic oxidation methods to meet the Class I discharge standards of the“Integrated Wastewater Discharge Standards”(GB 8978-1996),which specify ammonia nitrogen at 15 mg/l and COD at 100 mg/l.The experimental results indicate that a sodium hypochlorite dosage with a mass ratio of 1:8 can achieve the desired ammonia nitrogen concentration.In the Fenton oxidation process,a hydrogen peroxide dosage of 3.5 mL/L with a molar ratio of 1:3 for ferrous sulfate results in a COD removal rate of 57%.MAP precipitation achieves a 58% removal rate for ammonia nitrogen by utilizing existing magnesium ions.However,only the electrocatalytic oxidation method can simultaneously meet the standards for both ammonia nitrogen and COD removal.Considering practical considerations,the combination process of ammonia optimization at the front end,sodium hypochlorite oxidation,and electrocatalysis proves to be an economically efficient method for achieving compliant discharge.